Drain the oysters and place the oyster liquor in a pan with heavy cream, clam juice, wine, parsley, thyme and bay leaf over medium high heat. Simmer and reduce the liquid to yield 1 1/4 cup liquid. Remove from the heat and discard the parsley and bay leaves.
Melt 2 tablespoons of the butter in another saucepan. Add the flour and cook slowly for 3 minutes, stirring constantly. Add the cream mixture and continue to stir until thickened, 5 minutes. Cool slightly and add the oysters. Season with salt and pepper.
Butter a 4-cup gratin dish.
Place the bread crumbs and cracker crumbs in a bowl. Pour the remaining butter over bread and cracker crumbs and toss lightly. Spread one-third crumbs on bottom of dish and cover with half the oysters and sauce. Repeat. Top with remaining crumbs and bake in a 350 F oven until golden, about 35 minutes. Serve immediately.
1 1/2 pints (about 3 cups) fresh oysters with their liquor
1/2 cup (120 ml) heavy cream
1/2 cup (120 ml) bottled clam juice
1/2 cup (120 ml) dry white wine (Sauvignon Blanc)
4 sprigs parsley
Pinch of dry thyme
1 bay leaf
8 tablespoons unsalted butter, melted
1 tablespoon all-purpose flour
Salt and freshly ground pepper
1 cup dry bread crumbs
2 cups medium-coarse Saltine cracker crumbs